Piston contraptions such as the classic piston elevators no longer work as they should due to piston timing

When using simple piston elevators using sticky pistons, observers and redstone, the elevator will first start by travelling upwards as expected, before pausing in mid-air repeatedly switching between going upwards then downwards before finally returning to the ground level (bearing in mind that my intention was to travel to the top floor of my structure, not the ground floor.

 

I tested multiple 'simple' elevator designs and the same issue arose.

Some of the designs I tested were all replicated from these videos:

https://m.youtube.com/watch?v=cNbV3-Wf4KA

https://m.youtube.com/watch?v=ZE5uhC0Vz1c

(Sn: I am not the content creater and am only using these videos for the purpose of examples)